Weather Clouds Endeavour's Third Attempt at ISS Mission

NASA says all systems are go for a July 11 liftoff to the International Space Station but predicted showers and thunderstorms may postpone the 16-day mission to deliver the final permanent components of Japan's Kibo laboratory complex. Forecasters predict only a 40 percent chance for Endeavour to hit the launch window.

Grounded twice in June by a potentially dangerous launch pad hydrogen leak,
the space shuttle Endeavour's third attempt to lift off for the International
Space Station is threatened by a far more mundane but equally lethal issue: bad
weather.

Liftoff is scheduled for July 11 at 7:39 p.m. EDT,
but due to expected showers, thunderstorms and anvil clouds in the area, NASA
said July 9 the launch is only a 40 percent go. "That is always the
remaining issue that we have," NASA Test Director Steve Payne said in a
Thursday briefing. "If there's a hole in the clouds, we'll go for it. If
not, then we'll go for it the next day. But we would rather get it done on
Saturday."

Payne added that all others systems are go. The seven-person crew spent July 9
reviewing their flight plans, relaxing and checking out their launch-and-entry
suits. "All systems are in excellent shape," Payne said. "The STS-127
flight crew, Endeavour and launch team are ready to go."

Endeavour is scheduled to dock at the ISS July 13 with a cargo bay full of work
that includes what Endeavour Commander Mark Polansky calls "really big
pieces of equipment" and will require five spacewalks over the course of
the 16-mission. The primary mission purpose is to deliver the final permanent
components of Japan's
Kibo laboratory complex, a literal "front porch" on the ISS for
space-exposed science experiments.

After the crew's frustrating June, Polansky said, "I can tell you that
this crew and the entire operations team are both eager and ready to get to
work. Hopefully the next time we talk to you will be from orbit."

The Endeavour's original launch date was June 13, but it was canceled 5 hours
before launch due to a potentially dangerous vent line hydrogen gas leak. NASA
tried again on June 17 but called the mission when the hydrogen leak
reappeared. The leaks were similar to one that NASA encountered while trying to
launch Discovery four months ago.

That flight was delayed four days because of the problem and shortened as well.
Atlantis, however, encountered no such trouble during its countdown in May for
the Hubble Space Telescope repair mission.

Since the Endeavour crew stood down June 17, NASA engineers have pinpointed the
leak to a plate that attaches the vent line to Endeavour's external fuel tank.
The plate was slightly misaligned, allowing a small leak to happen during the
fueling process. After NASA completed a fueling test July 1, the space agency
declared the problem fixed.

"This one I feel really good about, that
we've got that problem licked and we're not going to see another GUCP [Ground
Umbilical Carrier Plate] leak again on the next
launch attempt," Mike Moses, head of
the shuttle's mission management team,
told reporters.

Once the Endeavour reaches the ISS, things will be as busy inside the
shuttle and space station as the spacewalkers, with all three of the available
robotic arms being put to use, sometimes all on the same day. The shuttle's
Canadarm and the station's Canadarm2 will be put through their regular paces
for surveys, unloading cargo and moving equipment and spacewalkers around, and
a new Japanese robotic arm will be making its debut to transfer science
experiments.